The totally blind, unable to perceive light, are often afflicted with a rare sleep disorder

When Jerry Berrier dreams, he hears and touches and smells and talks, but he doesn’t see. Blind since birth, he rarely remembers his dreams, however, because his sleep has been so poor.

At 15, Berrier had both of his eyes removed and lost the little light perception he had as a child. Ever since, the Everett resident, now 60, has battled a vicious sleep cycle — a few days of sleep followed by weeks of hardly any. The bouts of sleeplessness come suddenly and subside without warning. When they hit, Berrier can’t sleep more than a couple hours a night, no matter how tired he is.

Though physicians haven’t given him a formal diagnosis, scientists believe he suffers from a rare condition called non-24 sleep-wake disorder, or “non-24.” The chronic condition is characterized by a body clock that is out of synch with the 24-hour cycle of the Earth day.

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Non-24 can affect those with normal vision, but it especially plagues the totally blind who can’t perceive light, the strongest external signal that keeps the brain’s sleep-wake cycle aligned to the pattern of night and day. Of approximately 100,000 totally blind people in the United States, anywhere from 55 percent to 70 percent of them may suffer from non-24, according to Harvard neuroscientist Steven Lockley, one of the lead researchers in an ongoing clinical trial investigating sleep disorders in the blind. With 25 sites around the country, it’s the largest study of non-24 to date. Berrier is a participant in Boston.

The toll of having an internal clock in competition with the 24-hour world can be high, adding another layer of challenge to life without sight.

“There are some people who have said to me that having this sleep problem is worse than being blind,” Lockley said. “It’s a very difficult concept for sighted people to imagine — what could be worse than losing your vision?”

Randy Pierce, 46, of Nashua, N.H. is also part of the Boston study. In 1989, one year out of college, he was struck by a mysterious neurological disorder. In two weeks, it had ravaged his eyes and reduced his sight to fuzzy tunnel vision. In 2000, he went totally blind.

That was also the year he stopped sleeping well. In the 13 years since, Pierce said he has averaged three to four hours of sleep a night.

“Blindness is a visible challenge but this sleep disorder is totally invisible. Nobody would have any idea why I felt sick or unfocused, and they would judge,” Pierce said. “I would feel dumb and I’m not a dumb man. I would feel lazy, and I’m not a lazy man. It’s a very powerful invisible malady.”

The cause of Pierce’s sleep troubles, like Berrier’s, can be traced to a malfunctioning body clock. The “clock” is composed of two structures deep in the brain, each about the size of a grain of rice. Cells in these structures send out waves of electrical and chemical pulses, keeping the body alert during the day and putting it to rest at night.

Most people’s internal clocks naturally run slightly longer than 24 hours. Among the sighted, the clock is reset each day by signals from light-sensing cells in the eyes. But those who are totally blind lack this master reset mechanism.

In theory, a blind person with a cycle of 24.5 hours would feel ready for sleep 30 minutes later each day. In about three weeks — as the body’s natural bedtime inches its way around the clock — the brain’s “biological night” would be in the middle of the afternoon. This is when weeks of bad sleep suddenly strike for blind people struggling to maintain a normal schedule. Their fatigue is similar to that of someone traveling across time zones.

“If you are jet lagged you might feel this way for a few days — but you don’t feel this way for life,” said Lockley, who also works in the Division of Sleep Medicine at Brigham and Women’s Hospital.

For Pierce, non-24 compromises the alertness and memory he said are critical for a blind person.

Remembering how the clothes are stacked in his closet, or where the keys are, or the path to an unfamiliar place become difficult during sleepless periods. He records reminders into his phone constantly so he won’t miss appointments.

“As a blind guy, I have to be concentrating all the time,” he said. “I have to remember where the door is and where the counters are just so I can get around.”

For both Berrier and Pierce, maintaining social and professional lives can be a challenge. Berrier, a technology consultant at the Perkins School for the Blind, has kept a job for most of his life but often skips evening activities with friends. In sleepless weeks, Pierce is forced to schedule a day of recuperation for every day of work running his nonprofit or speaking at schools.

Over the years, both men have been diagnosed with everything from depression to narcolepsy to insomnia. They both have tried a host of sleeping pills, to no avail.

There are no medications approved by the US Food and Drug Administration to treat non-24. Some people have found relief from synthetic supplements of the hormone melatonin, which sends a “nighttime” signal to the body clock. But the treatment doesn’t work for everyone.

The ongoing clinical trial is testing a candidate drug called tasimelteon that scientists hope will be more effective in treating non-24.

The drug — developed by Washington, D.C.-based Vanda Pharmaceuticals, which is paying for the study — has a similar structure to melatonin. Lockley said that if approved, it will be more precisely dosed and administered than melatonin, which, as a dietary supplement, is not regulated by the FDA.

Harvard scientist J. Woodland Hastings, a pioneer in studying biological rhythms who is not involved in the trial, noted the importance of understanding exactly how this drug is different from melatonin, beyond being patentable and thus potentially profitable for Vanda.

Yet Hastings acknowledged the benefit that a prescription drug for non-24 could have in the medical world. “I do think a physician would be reluctant to prescribe melatonin without some kind of FDA regulation,” he said.

The development of an effective treatment could mean more than a good night’s sleep for those with non-24. According to Lockley, the disorder may interfere with the body’s regulation of metabolism, mood, and cognition.

“If you imagine that all of the organs in the body are members of an orchestra playing their own tunes, the master body clock is the conductor, synchronizing everyone to play in time,” Lockley said.

Berrier’s wife, Elaine, said non-24 has been a part of their entire 39 years of married life. Elaine, 60, is sighted, but as a retired nurse, she knows the toll of working an overnight shift, which has similar effects on a person’s body. She worries about how decades of similar fatigue have affected her husband.

“He often only gets three hours of sleep a night — I know that can shorten a life,” she said.

For Pierce, sleep loss has caused longer healing times. In the mid-2000s, he endured several neurological treatments to help the region of his brain that controls balance. He said that during his recuperation wounds took longer than normal to mend.

Both men are now taking tasimelteon daily, and have noticed improvement. They said they plan to use the drug if it hits the market, though Pierce wonders how he would afford the drug if it’s expensive.

The drug hasn’t worked perfectly for Berrier, but he now is more likely to have one night of bad sleep rather than weeks.

Last year, while on the treatment, Pierce became the first blind person (and his pup, The Mighty Quinn, the first guide dog) to climb all 48 of the 4,000-foot peaks in New Hampshire’s White Mountains in a single winter.

He said he would have attempted the winter climbs regardless, but the extra sleep made the ascents that much swifter.